1. Field of the Invention
The invention herein disclosed relates to medical devices for drainage of fluids from a patient during treatment. More particularly it relates to a system for drainage of fluid which unnaturally collects in the pleural space adjacent to the lung of a patient.
2. Prior Art
Pleural effusion is a medical condition which occurs when too much fluid collects in the pleural space of a patient. The pleural space is located in the chest cavity between the two layers of the pleura. It is more commonly known as “water on the lungs.” Symptoms of such include: shortness of breath, chest pain, gastric discomfort, and coughing.
In humans, there are two thin membranes located in the chest cavity. One such membrane is the visceral pleura which is a lining of the lungs. A second such membrane is the parietal pleura which covers the inside of the chest wall.
In healthy individuals, there are small blood vessels in these pleural linings which produce a small amount of fluid continually. This fluid provides a lubricant for the opposing two pleural membranes allowing them to slip and glide smoothly against each other another during the individual's breathing movements.
Should extra fluid accumulate, that excess fluid is taken up by blood and lymph vessels, thereby maintaining a delicate balance of sufficient fluid for lubrication but not too much to cause problems. However, when an individual either produces too much fluid or some other internal problem prevents normal body removal, the result is an excess of pleural fluid which forms the pleural effusion. The most common causes of pleural effusion are diseases of the heart or lungs or an inflammation or infection of the pleura.
The accumulation of fluid, especially in patients who are already ill, is physically very uncomfortable. It can make it hard, if not painful, for the patient to breathe along with secondary infections which can exacerbate an ill patient's condition causing further deterioration. Consequently, conventional treatment calls for the removal of the excess fluid causing the pleural effusion for both the patient's comfort and their well being.
There are many devices and methods employed by medical professionals to drain excess fluid which accumulates in such pleural effusions. A widely used device and method employs a catheter or tube which is inserted through the chest wall such that the axial cavity of the tube is in communication with the pleural space where the fluid is accumulating. At a distal end of the tube, exterior to the patient's body, a vacuum source is engaged to the axial cavity to pull the fluid from the cavity. The distal end of the tube must be sealed when not being employed under negative air pressure or air and contaminated fluids will leak back into the chest cavity through the axial cavity.
One popular device for this treatment features a duckbill valve on the distal end of the tube leading from the patient's chest. A tube, under negative pressure, is inserted through the duckbill valve and evacuates fluid from the chest tube and chest. Once the tube is removed from the valve it reseals on its own.
However, using a duckbill, or other tube-insertion activated valve has recently been found to be a source of danger in treating the patient. Because the valve is activated by the exterior of a catheter or tube inserted between two internally housed biased blades, the blades are subject to contamination from bacteria and contaminants on the exterior of the inserted tube or from the interior of the tube once so inserted.
Removal of the inserted vacuum tube leaves the valve members inside their housing in a position where they cannot be cleaned. Bacteria, viruses, and other contaminants can thus be positioned within the housing of the duckbill valve safely protected from the air outside and in contact with an excellent food source in the form of leftover pleural fluid inside the valve. The bacteria, viruses or other contaminants also have a clear pathway to the interior of the chest cavity through the axial cavity of the chest tube. The design is thus inherently flawed in that it cannot be cleaned and is subject to constant contamination by tube insertion into the valve to activate it.
There are other systems for draining the pleural area inside the chest cavity but those with a chest tube which must have a sealing valve on the distal end are all subject to contamination.
As such, there exists an unmet need for a device and method which will employ a chest tube to drain fluid from a pleural effusion but is resistant by design to potential introduction of bacteria, viruses, and contaminants during use. Such a device should employ a connection at the distal end of the chest tube, which may be cleaned and then sealed when not in use to maintain it in a sterile condition. Such a device should allow for multiple drainage sessions, using vacuum sources which are easily engaged to the distal end of the chest tube, in a manner that does not introduce bacteria or viruses or such into the axial cavity leading to the patient's chest. Such a device should avoid the use of hard to clean tubular inserts, which most certainly over time will introduce contaminants or pathogens into the chest tube.